A golf club head with a laser welded polymer insert

ABSTRACT

A method for laser welding a polymer insert within a recess of a golf club head is disclosed herein. Also disclosed is a golf club head having a laser welded polymer insert. The invention comprises laser welding a transparent polymer insert to a base polymer insert that has a heat absorbing color such as black or blue. The base polymer insert may also have an indicia thereon which is visible after laser welding the transparent polymer insert.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a golf club head with a polymer insert. More specifically, the present invention relates to a golf club head with a laser welded polymer insert.

2. Description of the Related Art

Throughout the history of golf, which dates back to as early as 1457, various techniques have been used to enhance the hitting characteristics of golf club heads. Golf club heads having inserts for the striking portion have been used at least as far back as 1880's when leather face irons were manufactured in Scotland. Golfer's in the 1890's were able to purchase putters with faces composed of gutta percha. More recently, inserts composed of various materials and shapes have been put forth by the creative geniuses of the golf industry to provide golfers with better feel and control of the golf ball.

One example is an ODYSSEY® putter having a STRONOMIC® insert that is disclosed in Magerman et al., U.S. Pat. No. 5,575,472 for a Golf Putter Head Having Face Insert And Method Of Forming The Same. The Magerman et al. Patent discloses a putter head with a recess into which is poured or inserted a resinous material which cures and is subsequently milled to produce the putter.

Another example is Pond, U.S. Pat. No. 5,524,331 for a Method For Manufacturing Golf Club Head With Integral Inserts that discloses a method for casting a graphite-epoxy composite insert within a recess of a face of a metal club head. The golf club head of the Pond Patent is directed at displacing the weight away from the center and increasing the moment of inertia.

Another example is Schmidt et al., U.S. Pat. No. 5,485,997, for a Golf Putter Head With Face Plate Insert Having Heightened Medial Portion, that discloses a putter head with a face plate composed of a non-metallic material such as an elastomer. The overall construction of the putter head of the Schmidt et al. Patent is directed at enlarging the sweet spot and improving the peripheral weighting.

Yet another example is found in Baker et al., U.S. Pat. No. 5,931,743 for a Putter Having Club Head With A Golf-Ball Engagement Insert And A Shaft Rearwardly Of The Insert which discloses a putter with a center shaft and an insert composed of a thermoplastic polyurethane. Another example is Jepson et al., U.S. Pat. No. 3,937,474 for a Golf Club With Polyurethane Insert, which discloses a wood having an insert on its striking face that is composed of a polyurethane formed from a tolylene diisocyanate polyether terminated prepolymer and a curing agent. The hardness of this insert varies from 40 to 75 Shore D, and a Bayshore Resiliometer of 17 or above. The polyurethane insert is claimed to impart additional energy to the golf ball during a golf hit.

Chen et al., U.S. Pat. No. 5,743,813 for a Golf Club Head discloses a wood composed of stainless steel with a three layer face having a first stainless steel layer, an elastic layer and a second stainless steel layer. The three-layer face does not absorb the hitting force when a golf ball is hit.

Fisher, U.S. Pat. No. 5,458,332, for a Golf Putter Head With A Cushioning Face, discloses a set of golf putters, each having an insert composed of polyurethane with a hardness in the range of 70 Shore A to about 80 Shore D. The rebound factor of each of the inserts is in the range of 12.5% to 50%, and the inserts are formulated to affect a reproducible direct linear relationship between the rebound factor and the distance of the putt.

Yet another example is McGeeney et al, European Patent Application Number 0891790 for a Multiple Density Golf Club Head And Method Of Manufacturing which discloses a putter with a central segment composed of a thermoplastic elastomer or a thermoset polymer. Possible thermoplastic elastomers include styrene co-polymers, co-polyesters, polyurethanes, polyamides, olefins and vulcanates. Possible thermoset polymers include epoxides, polyimides and polyester resins. The central segment has a minimum durometer hardness of Shore D 50. The central segment is bounded by metallic heel and to portions. However, the use of inserts is restrained in order to maintain the integrity of the game of golf.

In this regard, the Rules of Golf, established and interpreted by the United States Golf Association (“USGA”) and The Royal and Ancient Golf Club of Saint Andrews, sets forth certain requirements for a golf club head. The requirements for a golf club head are found in Rule 4 and appendix II. A complete description of the Rules of Golf are available on the USGA web page at www.usga.org. Although the Rules of Golf do not expressly state specific parameters for an insert for a putter, the Rules of Golf have been interpreted to establish that an insert for a putter should have a Shore A hardness greater than 87±2%, have a constant thickness, have a thickness of at least 0.125 inches, and not act like a spring.

The prior art is absent a golf club head that has an insert composed of a material that is soft, but above the USGA requirements, and has a sufficient Bayshore rebound to provide a golf ball with the necessary distance to reach the hole.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed at a method for manufacturing a golf club head with an insert using laser welding. The use of laser welding allows for a base insert to have an indicia that is visible through a transparent polymer insert.

Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE INVENTION

FIG. 1 is a perspective view of one embodiment of the golf club head of the present invention without an insert in the recess of the club head body.

FIG. 1A is a front view of the club head of FIG. 1 with the insert placed therein.

FIG. 1B is a side view of the club head of FIG. 1.

FIG. 1B is a rear view of the club head of FIG. 1.

FIG. 1D is a top view of the club head of FIG. 1.

FIG. 2 is a front view of the club head of FIG. 1.

FIG. 3 is a front view of a club head with an insert having an indicia thereon.

FIG. 4 is a cross-section view of the club head of FIG. 2 along line 4-4.

FIG. 5 is an exploded view of a club head with two inserts.

FIG. 6 is an isolated enlarged view of the transition region between the two inserts of a club head.

FIG. 7 is an exploded cross-section view of a club head with two inserts.

FIG. 8 is a side view of a precursor club head undergoing laser welding.

FIG. 9 is a flow chart of a general method of laser welding.

FIG. 10 is a front view of a wood club head with an insert.

FIG. 11 is a front view of an iron club head with an insert.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIGS. 1 through 1D, a putter is generally designated 50. The putter 50 includes a club head 52 having a body 54 with a front face 56 with a recess 58 therein. The club head 52 also includes a transparent polymer insert 60 disposed within the recess 56. The transparent polymer insert 60 preferably extends along most of the face 56 from a heel 62 of the club head 52 to a toe 64 of the club head 52, and from a sole 66 of the club head 52 to a crown 68 of the club head 52. The club head 52 also preferably has a hosel 70 for connection to a shaft 72. Opposite of the front face 56 of the club head 52 is a rear 74 of the club head 52.

The body 54 of the club head 52 is preferably composed of a metallic material such as titanium, titanium alloy, amorphous metals, brass, carbon steel, or stainless steel. However, those skilled in the pertinent art will recognize that the body 54 may be composed of other materials without departing from the scope and spirit of the present invention. Further, the non-insert portion of the face 56 may be smooth or textured to provide a consistent or non-consistent surface with the exterior surface of the insert. Additionally, the body 54 may be specifically weighted to provide a specific center of gravity for the putter 50.

The putter 50 illustrated in FIGS. 1-1D is flanged blade putter, however, those skilled in the pertinent art will recognize that other similar putter designs such as a mallet or semi-mallet may be utilized without departing from the scope and spirit of the present invention.

Referring specifically to FIG. 1, the recess 58 of the body 54 is defined by a recess face wall 80 which is substantially parallel with the transparent polymer insert 60, and a recess edge wall 82 which is substantially perpendicular to the recess face wall 80. The recess face wall 80 defines the depth of the recess 58. The recess edge wall 82, as shown in FIG. 1, is composed of a bottom recess edge wall 82 a, a heel recess edge wall 82 b, a top recess edge wall 82 c and a toe recess edge wall 82 d. The recess edge wall 82 defines the shape of the recess 58, and the length of the recess edge wall 82 is determined by the depth of the recess 58.

The putter 50 of FIGS. 1-1D is a flanged blade style putter. The rear 74 of the club head 52 has a rear wall 75 and a flanged portion 77. The transparent polymer insert 60 preferably occupies more than 80% of the area of the face 56 of the club head 52. The transparent polymer insert 60 varies in shape and thickness depending on the design of the putter 50. A preferred shape of the transparent polymer insert 60 is a trapezoidal shape with curved corners. An alternative shape is a trapezoidal shape with a panhandle, not shown.

As shown in FIGS. 2-5 and 7, a preferred embodiment of the club head 52 has a base insert 61 that is preferably adhered to the recess face wall 82. The base insert 61 preferably has a thickness that ranges from 1.0 millimeter to 10 millimeters, more preferably from 1.5 millimeters to 7 millimeters, and even more preferably 2.0 millimeters to 5.0 millimeters, and most preferably 3.0 millimeters. The transparent polymer insert 60 preferably has a thickness that ranges from 1.0 millimeter to 10 millimeters, more preferably from 1.5 millimeters to 7 millimeters, and even more preferably 2.0 millimeters to 5.0 millimeters, and most preferably 3.0 millimeters. In a preferred embodiment, the thickness of both the base insert 61 and the transparent polymer insert 60 defines the depth of the recess 58.

The base insert 61 is preferably colored, as opposed to transparent. In a preferred embodiment, the base insert 61 has a heat absorbing color. Most preferably the color is selected from the group of black, blue (navy, royal, marine, light), brown, purple, red, orange, grey, green or other similar colors.

The polymer material for the transparent polymer insert 60 and the base insert 61 is preferably a thermoplastic polyurethane material. Alternative polymer materials that may be utilized for the transparent polymer insert 60 and the base insert 61 include: polymers from Bayer Corporation sold under the TEXIN brand such as TEXIN 4215, TEXIN 4210, TEXIN 270, TEXIN 4210 T2, TEXIN 270 T2, TEXIN 4215 T2 and TEXIN 4215 T3, which are thermoplastic polyurethanes and thermoplastic polyurethane and polycarbonate blends; polymers from BASF corporation such as TERLURAN EGP-7, TERLURAN HI-10, TERLURAN GP-22, which are ABS polymers, ULTRAMID A3HG5, LURANS 778 T1 and LURAN S 778 T/TE T2, which are ABS and polyamide blends, and TRIAX 1120, which is an ABS and polyamide blend; polymers from Du Pont Chemicals such as HYTREL 7246 thermoplastic polyester elastomer and HYLENE 58D polymer and SURLYN ionomers; polymers from GE Polymers such as NORYL PPX/PPX7115 polyphenylene ether and polystryene blend, LEXAN EXL 1330 T2, LEXAN EXL 1330 T3, LEXAN ML 6143/C1000, LEXAN 1330/ML6143, LEXAN ML6143H and LEXAN 1330, which are amorphous thermoplastic polymers, CYCOLOY C1000HF T1, CYCOLOY C1000HF T2, CYCOLOY C1000HF T3, CYCOLOY C1000HF T4 AND CYCOLOY C1000HF T5, which are ABS and polycarbonate blends; polymers from Atofina corporation sold under the brands ATOFINA 3429, ATOFINA 3467 and ATOFINA 7823 MZ; polymers from BP Chemical sold under the brand BAREX 210, which is an E acrylonitrile-methyl acrylate copolymer; polymers from Chevron corporation sold under the brands BK-12, KR03 and BK10/NAS90 blend; polymers from Exxon Mobil chemical sold under the brands PP1024E4, PP1043N, PP7033N, PP7032E2T1, PP7032KN and PP7032E2T2; polymers from Huntsman Chemical sold under the brand IROGRAN 113557; polymers from RTP corporation sold under the brands 1299-A 80D w/glass, 1299-B 80D without glass, RTP 4085 and Nylon 6 with nano; polymers from Uniroyal sold under the brand AN2501750 blend T1, AN2501750 blend T2 and LF750D; and LUMOGEN IR 788 and LUMOGEN IR 765 from BASF.

The Shore D hardness of the polymer material for the insert 60 preferably ranges from 40 to 70 Shore D, more preferably from 50 to 65 Shore D, and is most preferably approximately 60 Shore D. The base insert 61 preferably has a similar Shore D hardness.

As shown in FIG. 3, a front surface 63 of the base insert 61 has an indicia 77 thereon. The indicia 77 is visible through the transparent polymer insert 60 and is protected during use from deterioration by the transparent polymer insert 60. The indicia 77 is preferably a corporate logo, name of the golfer, greeting, or slogan. The indicia 77 is preferably printed on the front surface 63 of the base insert 61. Alternatively, the indicia 77 is embossed of the front surface 63 of the base insert 61.

A general method of laser welding is generally designated 100, as shown in FIG. 9. In a preferred embodiment, the method 100 involves laser welding the transparent polymer insert 60 to the base insert 61. Laser welding involves passing laser light through the transparent polymer insert 60 (laser transparent polymer insert) onto the base insert 61 (laser absorbent polymer insert). The absorbed laser energy softens and melts the transparent polymer insert 60 and the base insert 61. More precisely, the laser energy absorbed by the base insert 61 heats the base insert 61 which softens and melts a transition region 71 which includes the front surface 63 of the base insert 61 and an interior surface 65 of the transparent polymer insert 60, as shown in FIG. 6. Upon cooling, the transparent polymer insert 60 is adhered to the base insert 61.

Returning the flow chart of FIG. 9, at step 102, the base insert 61 is adhered to the recess face wall 82 of the recess 58 of the club head 52. The base insert 61 is preferably adhered using an adhesive such as an epoxy. However, the base insert 61 alternatively may be mechanically adhered using bolts, press-fitting or other well-known methods. Next, at step 104, the transparent polymer insert 60 is placed onto the front surface 63 of the base insert 61 and thereby fitted within the recess 58. At step 106, the transparent polymer insert 60 is irradiated with laser energy 91 from a laser device 90, as shown in FIG. 8. The irradiation of laser energy is performed for a time period preferably ranging from 0.1 second to 10 minutes, and more preferably from 1.0 seconds to 1 minute. The irradiation period will depend on the materials utilized, the power of the laser and the thickness of the materials.

The laser device is preferably an infrared laser having a wavelength ranging from 800 nanometers to 950 nanometers. A preferred laser device is a Nd-YAG diode laser. A preferred laser welding system is available from Dukane Company of St. Charles, Ill. Other laser welding systems commercially available include a POLYSCAN system, a STARWELD DIODE system and a STARSHAPE C system, all of which are available from Rofin-Sinar Technologies of Hamburg Germany.

In an alternative embodiment, a laser absorbent polymer layer 61′ (not shown) is adhered to the recess face wall 82 as a substitute for the base insert 61. In such an embodiment, the laser absorbent polymer layer 61′ absorbs the laser energy to melt the transparent polymer insert 60 for adherence thereto. The laser absorbent polymer layer 61′ has a thickness preferably ranging from 0.5 millimeters to 5 millimeters, and preferably has a heat absorbing color as discussed above.

FIG. 10 is illustrates yet another utilization of the transparent polymer insert 60 a and base insert 61′ (not shown) in a wood club head 52 a. The transparent polymer insert 60 a occupies most of the face 56 a, from the heel 62 a to the toe 64 a, and from the sole 66 a to the crown 68 a. The body 54 a of the club head 52 a may be hollow, unlike the putters 50 of the previous embodiments. Further, the recess face wall, not shown, of the recess 58 a will not abut the rear wall, not shown, unlike the putters 50 of the previous embodiments. The body 54 a may be composed of titanium, or steel. FIG. 11 illustrates a further embodiment where the transparent polymer insert 60 b and base insert 61′ are used on the face 56 b of an iron club head 52 b.

From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims. 

1. A method for manufacturing a golf club head with a polymer insert, the method comprising: placing a transparent polymer insert into a recess of a face of a golf club head, the recess having a colored polymer layer forming a back wall of the recess, the colored polymer layer having a front surface, a interior surface of the transparent polymer insert contacting the front surface of the dark colored polymer layer; and irradiating the transparent polymer insert with a laser having a wavelength ranging from 800 nanometers to 950 nanometers to laser weld the transparent polymer insert to the colored polymer layer.
 2. The method according to claim 1 wherein the transparent polymer insert and the colored polymer layer are composed of a polyurethane material.
 3. The method according to claim 1 wherein the transparent polymer insert has a thickness ranging from 1.0 millimeter to 10 millimeters.
 4. The method according to claim 1 wherein the transparent polymer insert is irradiated for a time period ranging from 1 second to 1 minute.
 5. The method according to claim 1 further comprising attaching the colored polymer layer to an interior wall of the recess of the golf club head with an adhesive.
 6. The method according to claim 1 wherein the colored polymer layer has an indicia on the front surface.
 7. The method according to claim 1 wherein the colored polymer layer is a colored polymer insert having a thickness ranging from 1.0 millimeter to 10 millimeters.
 8. The method according to claim 1 wherein the golf club head is a putter-type golf club head.
 9. The method according to claim 1 wherein the golf club head is a wood-type golf club head.
 10. The method according to claim 1 wherein the golf club head is an iron-type golf club head.
 11. The method according to claim 1 wherein a body of the golf club head is composed of titanium.
 12. The method according to claim 1 wherein a body of the golf club head is composed of stainless steel.
 13. The method according to claim 1 wherein the colored polymer layer is black in color.
 14. The method according to claim 1 wherein the colored polymer layer is navy blue in color.
 15. The method according to claim 1 wherein the colored polymer layer is purple in color.
 16. The method according to claim 1 wherein the colored polymer layer is green in color.
 17. A method for manufacturing a putter-type club head with a polymer insert, the method comprising: adhering a base polymer insert to a rear wall of a recess of a face of a putter-type club head, the base polymer insert having a heat absorbing color, the base polymer insert having a thickness ranging from 1.0 millimeter to 10 millimeters, the recess having a depth that is at least twice the thickness of the thickness of the base polymer insert; placing a transparent polymer insert into the recess of a face of the putter-type club head, an interior surface of the transparent polymer insert contacting a front surface of the base polymer insert; and heating the base polymer insert with a laser having a wavelength ranging from 800 nanometers to 950 nanometers by transmitting the laser through transparent polymer insert to laser weld the transparent polymer insert to the base polymer insert.
 18. The method according to claim 17 wherein the transparent polymer insert and the base polymer insert are each composed of a polyurethane material.
 19. The method according to claim 17 wherein the transparent polymer insert has a thickness ranging from 1.0 millimeter to 10 millimeters.
 20. The method according to claim 17 wherein the base polymer insert is heated for a time period ranging from 0.1 second to 1 minute.
 21. The method according to claim 17 wherein the base polymer insert has an indicia on the front surface.
 22. The method according to claim 17 wherein the heat absorbing color for the base polymer insert is selected from the group consisting of black, blue, brown, purple, green, red, orange and grey.
 23. A golf club head comprising: a club head body having a front face with a recess therein; a base insert disposed within the recess, the base insert having a thickness ranging from 1.0 millimeter to 10.0 millimeters, the base insert composed of a polyurethane material, the base insert having a heat absorbing color; a transparent polymer insert laser welded to a front surface of the base insert, the transparent polymer insert having a thickness ranging from 1.0 millimeter to 10.0 millimeters, the transparent polymer insert a Shore D hardness in the range of 40 to 60, and a Bayshore rebound in the range of 55 to
 70. 24. The golf club head according to claim 23 wherein the golf club head is a putter-type golf club head.
 25. The golf club head according to claim 23 wherein the golf club head is a wood-type golf club head.
 26. A method for manufacturing a golf club head with a polymer insert, the method comprising: placing a laser transparent polymer insert into a recess of a face of a golf club head, the recess having a laser absorbent polymer layer forming a back wall of the recess, the laser absorbent polymer layer having a front surface, a interior surface of the laser transparent polymer insert contacting the front surface of the laser absorbent polymer layer; and irradiating the laser transparent polymer insert with laser energy from a laser having a wavelength ranging from 800 nanometers to 950 nanometers to laser weld the laser transparent polymer insert to the laser absorbent polymer layer.
 27. A method for manufacturing a putter-type club head with a polymer insert, the method comprising: adhering a laser absorbent base polymer insert to a rear wall of a recess of a face of a putter-type club head, the laser absorbent base polymer insert having a thickness ranging from 1.0 millimeter to 10 millimeters, the recess having a depth that is at least twice the thickness of the thickness of the laser absorbent base polymer insert; placing a laser transparent polymer insert into the recess of a face of the putter-type club head, an interior surface of the laser transparent polymer insert contacting a front surface of the laser absorbent base polymer insert; and heating the laser absorbent base polymer insert with laser energy from a laser having a wavelength ranging from 800 nanometers to 950 nanometers by transmitting the laser energy through laser transparent polymer insert to laser weld the transparent polymer insert to the base polymer insert. 